Centrifugal recovery of solvent after biphasic wet extraction of lipids from a concentrated slurry of Nannochloropsis sp. biomass

Abstract

Wet extraction of lipids from a microalgae slurry requires efficient recovery of the solvent. The use of a non-polar solvent such as hexane allows physical recovery of the solvent by centrifugation, avoiding energy intensive distillation of the aqueous slurry. However, the kinetics and mechanisms of centrifugal separation of solvent from microalgae are yet to be investigated. In this study, hexane was used to perform biphasic extraction of lipids from a concentrated slurry of ca 50% ruptured Nannochloropsis sp. cells. The hexane droplet size of the resulting emulsion and the viscosity of continuous phase were characterised. The slurry of ruptured cells was highly viscous and shear-thinning. ..